d:\src>phpcallback_performance.php#1, result is 50, done in 0.000415#2, result is 50, done in 0.000270d:\src>phpcallback_performance.php#1, result is 50, done in 0.000413#2, result is 50, done in 0.000261d:\src>phpcallback_performance.php#1, result is 50, done in 0.000412#2, result is 50, done in 0.000273